There were no abnormalities noted in the previous recorded flights or service history that indicated any problems with the hinge bracket before the incident. The hinge bracket failed due to low cycle fatigue, which originated at the site of the identified impact damage. The impact damage created a stress riser, which developed into a fatigue crack over the operating life of the hinge bracket. The impact damage was located in an area that is protected once the bracket is installed. It is likely that the hinge bracket was damaged before or during installation and, given the relatively small size of the damage, was likely not noticed at that time. After installation, it would not have been possible to see the damage, and detection of the crack during subsequent inspections would have been very difficult. Airbus has positively identified one additional failure of this nature in a fleet of 240aircraft incorporating this type of hinge bracket. Of the 240aircraft produced, only 17 were reported to have incorporated the improved hinge bracket and only 7 of these remain in service worldwide, as of May2006. Although it is possible that another failure of this nature could occur in the future, there were no adverse effects on the flying characteristics of the aircraft; therefore, the risk of a catastrophic event is low. However, it is unlikely that the hinge bracket will fail unless the flaps are extended for take-off or landing. Therefore, in the event of another failure, the aircraft would most likely be over a populated area. The following TSB Engineering Laboratory reports were completed: LP 033/2006 - Flap Tab Assembly LP 034/2006 - FDR CVR Analysis These reports are available from the Transportation Safety Board of Canada upon request.Analysis There were no abnormalities noted in the previous recorded flights or service history that indicated any problems with the hinge bracket before the incident. The hinge bracket failed due to low cycle fatigue, which originated at the site of the identified impact damage. The impact damage created a stress riser, which developed into a fatigue crack over the operating life of the hinge bracket. The impact damage was located in an area that is protected once the bracket is installed. It is likely that the hinge bracket was damaged before or during installation and, given the relatively small size of the damage, was likely not noticed at that time. After installation, it would not have been possible to see the damage, and detection of the crack during subsequent inspections would have been very difficult. Airbus has positively identified one additional failure of this nature in a fleet of 240aircraft incorporating this type of hinge bracket. Of the 240aircraft produced, only 17 were reported to have incorporated the improved hinge bracket and only 7 of these remain in service worldwide, as of May2006. Although it is possible that another failure of this nature could occur in the future, there were no adverse effects on the flying characteristics of the aircraft; therefore, the risk of a catastrophic event is low. However, it is unlikely that the hinge bracket will fail unless the flaps are extended for take-off or landing. Therefore, in the event of another failure, the aircraft would most likely be over a populated area. The following TSB Engineering Laboratory reports were completed: LP 033/2006 - Flap Tab Assembly LP 034/2006 - FDR CVR Analysis These reports are available from the Transportation Safety Board of Canada upon request. Hinge bracket damage, which occurred either before or during installation, created a stress riser for a low cycle fatigue crack to develop and progress over the life of the part. The hinge bracket failed after the flaps were selected to the 25 setting while on approach to the Toronto/Lester B. Pearson International Airport. This allowed the flap tab to separate from the aircraft and strike a parked vehicle.Findings as to Causes and Contributing Factors Hinge bracket damage, which occurred either before or during installation, created a stress riser for a low cycle fatigue crack to develop and progress over the life of the part. The hinge bracket failed after the flaps were selected to the 25 setting while on approach to the Toronto/Lester B. Pearson International Airport. This allowed the flap tab to separate from the aircraft and strike a parked vehicle. Although in-flight separation of the flap tab presents little risk to the operating characteristics of the aircraft, the falling debris poses a risk of striking a populated area.Finding as to Risk Although in-flight separation of the flap tab presents little risk to the operating characteristics of the aircraft, the falling debris poses a risk of striking a populated area. Airbus is developing a repetitive inspection program (planned Inspection Service Bulletin [ISB] 57-0250) for the hinge bracket, and based on the results of that inspection program, will consider further modifications to the hinge bracket.Safety Action Taken Airbus is developing a repetitive inspection program (planned Inspection Service Bulletin [ISB] 57-0250) for the hinge bracket, and based on the results of that inspection program, will consider further modifications to the hinge bracket.